We have raised a potent monoclonal antibody (RBC-A) against blood Group A antigen. Our aims are to: (1) raise additional monoclonal antibodies to red blood cell alloantigens; (2) institute the technology for the production of human monoclonal antibodies with emphasis on the Rh system; and (3) complete the study on the commercial value of our monoclonal RBC-A as an effective in vitro diagnostic reagent. Long-term objectives to health relatedness: Develop new diagnostic tools for blood banking, genetic typing, paternity testing and forensic medicine: develop new pathogen free therapeutic tools such as those used in Rh incompatibility therapy. Methodology: Use microagglutination on fully phenotyped red cell panels for the quick screenings of hybridomas; utilize B cell enriched lymphycytes from individuals with high postnatal Rh titers for secondary in vitro stimulation with Rh positive red cells in producing human monoclonal antibodies; regarding RBC-A prove specificity, stability, potency and product uniformity biochemically by SDS-PAGE, IEF, Ig subclassing and serologically by agglutination, lysis, binding and inhibition assays. Phase I Implications for Phase II: We expect that by the end of Phase I we will have additional monoclonals in various phases of development and functional technology to produce human monoclonal antibodies; furthermore, we will have the data to prove that our RBC-A is a biologic product that meets and exceeds FDA standards. Commercial applications: The development of new monoclonal antibodies to red cell antigens will result in the creation of new biological products and diagnostic tests. The sale of ABO and Rh typing reagents in the U.S.A. alone is a yearly multi-million dollar industry. The untapped human monoclonal antibody industry is believed to hold promise for a billion dollar industry worldwide.